[V2] riscv: fix pfn_to_virt err in do_page_fault().

[liush]

The argument to pfn_to_virt() should be pfn not the value of CSR_SATP.

Signed-off-by: liush <liush at allwinnertech.com>
---
 arch/riscv/mm/fault.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index 716d64e..3e560ec13 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -198,6 +198,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
 		pmd_t *pmd, *pmd_k;
 		pte_t *pte_k;
 		int index;
+		unsigned long pfn;
 
 		/* User mode accesses just cause a SIGSEGV */
 		if (user_mode(regs))
@@ -212,7 +213,8 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
 		 * of a task switch.
 		 */
 		index = pgd_index(addr);
-		pgd = (pgd_t *)pfn_to_virt(csr_read(CSR_SATP)) + index;
+		pfn = csr_read(CSR_SATP) & SATP_PPN;
+		pgd = (pgd_t *)pfn_to_virt(pfn) + index;
 		pgd_k = init_mm.pgd + index;
 
 		if (!pgd_present(*pgd_k))
-- 
2.7.4